It is known that Bragg gratings impressed in optical fibers may be used to detect perturbations, such as, strain or temperature, at the location of the gratings, such as is described in U.S. Pat. Nos. 4,806,012 and 4,761,073 both to Meltz et al. In such a sensor, the core of the optical fiber is written with periodic grating patterns effective for reflecting a narrow wavelength band of light launched into the core. Spectral shifts in the transmitted and reflected light indicate the intensity of strain or temperature variations at positions of the grating corresponding to the associated wavelengths of the injected light. However, while it is known that the reflectivity (or transmission) wavelength profile (or spectrum) of the gratings shift as a function of an applied perturbation to the grating area, to date, a practical, whole system, using such fiber Bragg gratings, has not yet been discussed.
Thus, it would be desirable to provide a system for detecting the wavelength shift of fiber Bragg gratings that occurs due to static or dynamic strain, acoustic perturbations or other perturbations.